Nose And Paranasal Sinuses Short Question And Answers

Question 1. Describe the Maxillary Nerve under the following headings. (or) Maxillary air sinus

• Origin, Course, Branches, Distribution, Applied anatomy

Maxillary Nerve Origin:

• It arises from the trigeminal ganglion

Maxillary Nerve Course:

• It runs forwards in the lateral wall of the cavernous sinus below the ophthalmic nerve
• Leaves the middle cranial fossa by passing through the foramen rotundum
• It crosses the upper part of Pterygopalatine fossa
• Next it continues as the infraorbital nerve

Read And Learn More: BDS Previous Examination Question And Answers

Branches and their distribution:

1. In middle cranial fossa:

• Middle meningeal nerve to supply dura

2. In pterygopalatine fossa:

1. Zygomatic nerve
   • Passes anteriorly & laterally
   • Divides into
     1. Zygomaticofacial nerve- Pierces the orbicularis oris & supplies prominence of cheek
     2. Zygomaticotemporal nerve
        • Enters temporal fossa & supplies skin over the anterior temporal fossa region
2. Pterygopalatine nerve: Branches:
   1. Orbital branches- By means of inferior orbital fissure, supplies periosteum of orbit, posterior ethamoid cells & sphenoid sinus
   2. Nasal branches: Divides into posterior superior lateral & medial or septal branches
3. Palatine branches: Descends in pterygopalatine canal, divides into
   1. Greater or anterior palatine- supply hard palate
   2. Middle palatine-Sensory to soft palate
   3. Posterior palatine- Supplies mucous membrane to tonsil

3. Posterior superior alveolar nerve:

• Divides into many branches & descends downward to supply maxillary molars & their supporting gingivae

4. Branches in infraorbital groove & canal:

1. Middle superior alveolar nerve:
   • Supplies posterior part of maxillary sinus
   • Descends downward
   • Divides & supplies maxillary bicuspids
2. Anterior superior alveolar nerve:
   • Descend & divides
   • Supplies maxillary anteriors

5. Terminal branches on face:

1. Inferior palpebral- Supplies lower eyelid
2. External or lateral nasal- Supplies side of nose
3. Superior labial- Supplies upper lip

Maxillary Nerve Applied Anatomy:

• It carries the afferent limb fibres of the sneeze reflex
• Trigeminal neuralgia affecting maxillary nerve produces symptoms in the area of its distribution
• The nerve can be anaesthesized at the foramen rotundum

Question 2. Describe bone formation, features, opening, blood supply & nerve supply of lateral wall of nose (or) Lateral wall of nasal cavity. (or) Openings related to Lateral Wall of Nasal Cavity.
Answer:

Lateral wall of nose:

Lateral Wall of Nasal Cavity Bone formation:

• It is formed by following bones
• Nasal bone
• Frontal process of maxilla
• Lacrimal bone
  • Labyrinth of ethamoid with superior & middle conchae
  • Inferior nasal concha
  • Perpendicular plate of palatine bone
  • Medial pterygoid plate

Lateral Wall of Nasal Cavity Features:

• Bony wall is covered by mucous membrane & projects as three nasal conchae

1. Inferior nasal concha
   • It is separate bone, present horizontally
2. Middle concha
   • It is part of ethmoid labyrinth
3. Superior concha
   • It is smallest concha situated just above the posterior part of middle concha
   • The meatuses of the nose are passages beneath the overhariging conchae
   • There are three meatuses
     1. Inferior meatus
        • Lies underneath the inferior concha
     2. Middle meatus
        • Lies beneath middle concha
        • It presents
          1. Ethamoidal bulla
          2. Hiatus semilunaris
          3. Infundibulum
     3. Superior meatus
        • Present below superior concha
        • Area above superior concha is called sphenoethamoidal recess

Lateral Wall of Nasal Cavity Openings:

Lateral Wall of Nasal Cavity Blood supply & nerve supply:

Nerve supply:

• General sensory nerves are from trigeminal nerve
• Special sensory nerves are olfactory nerves

Venous drainage:

• Anteriorly-drains into facial vein
• Posteriorly- drains into pharyngeal plexus
• Middle part- drains into pterygoid plexus of veins

Question 3. Describe Maxillary Air Sinus & its relations
Answer:

Maxillary Sinus:

• It is largest of all sinuses
• It lies in the body of maxilla

Maxillary Air Sinus Size:

• Height-3.5 cm
• Width-2.5 cm
• Anteroposterior depth- 3.5 cm

Maxillary Air Sinus Boundaries:

• It is pyramidal in shape
• Base-directed medially towards lateral wall of the nose
• Apex-Directed laterally in the zygomatic process of the maxilla
• Roof- formed by Floor of the orbit
• Floor- Formed by alveolar process of maxilla

Maxillary Air Sinus Opening:

• It opens into middle meatus of nose in the lower part of the hiatus semilunaris
• A second opening is present at the posterior end of hiatus
• This opening is reduced in intact skull as it is overlapped by the following.

1. 1. Uncinate process of the ethamoid- from above
   2. Ethamoidal process of inferior nasal concha- from below
   3. Perpendicular plate of palatine bone- from behind
   4. Descending process of the lacrimal bone- from front

Maxillary Air Sinus Relations:

Maxillary Air Sinus Blood Supply:

Arterial Supply:

• Facial artery
• Infraorbital artery
• Greater palatine artery

Maxillary Air Sinus Venous Drainage:

• Facial vein
• Pterygoid plexus of veins

Maxillary Air Sinus Nerve Supply:

• Infraorbital nerve
• Anterior, middle & posterior superior alveolar nerve

Maxillary Air Sinus Lymphatic Drainage:

• Into Submandibular lymph nodes

Question 4. Describe gross anatomy of nasal septum. (or) Describe nasal septum. Give its blood supply, nerve supply, lymphatic drainage & applied anatomy (or) Nerve supply of septum of nose (or) Nasal septum
Answer:

• It is a median osseocartilagenous partition between the two halves of the nasal cavity

Nasal Septum Formation:

• It is partly formed by bone & partly by cartilage

1. 1. Bony part
      • It is formed by
        1. Perpendicular plate of ethmoid
        2. Vomer
        3. Accessory bones like
           • Nasal spine of frontal bone
           • Sphenoidal crest & rostrum
           • Palatine processes of maxillae & horizontal parts of palatine bone
   2. Cartilages are formed by
      • Septal cartilage
      • Septal process of lower nasal cartilage
      • Vomeronasal cartilage

Nasal Septum  Blood supply, nerve supply & lymphatic drainage:

• General sensory nerves arises from trigeminal nerve
• Special sensory nerves are olfactory nerves which are confined to the upper part of olfactory area

Nasal Septum  Applied anatomy:

Little’s Area:

• It is common site of epitaxis
• It is an area of formation of large capillary network called the Kiesselbach’s plexus
• It is formed by anastomosis of five arteries

1. 1. Sphenopalatine artery
   2. Superior labial branch of facial artery
   3. Anterior ethmoidal artery
   4. Greater palatine artery
   5. Nasal branches of facial artery
      • Pathological deviation of the nasal septum causes repeated attacks of common cold, allergic rhinitis, sinusitis, etc.

Question 5. Describe the lateral wall of Nasal Cavity under following headings:

1. Parts
2. Openings
3. Blood supply
4. Nerve supply

Answer:

Nasal Cavity Parts:

• Lateral wall of nasal cavity is divided into three parts
  • Anterior part- vestibule
  • Middle part- atrium of the middle meatus
  • Posterior part-containing conchae

Nasal Cavity Openings:

Nasal Cavity Nerve supply:

• General sensory nerves are from trigeminal nerve
• Special sensory nerves are olfactory nerves

Nasal Cavity Venous drainage:

• Anteriorly drains into facial vein
• Middle part drains into pterygoid plexus of veins
• Posteriorly drains into pharyngeal plexus

Question 6. Nasal septum
Answer:

Nasal septum Formation:

• It is partly formed by bone & partly by cartilage

1. Bony part:

• • • It is formed by
      1. Perpendicular plate of ethmoid
      2. Vomer
      3. Accessory bones like
         1. Nasal spine of frontal bone
         2. Sphenoidal crest & rostrum
         3. Palatine processes of maxillae & horizontal parts of palatine bone

2. Cartilages are formed by:

• Septal cartilage
• Septal process of lower nasal cartilage
• Vomeronasal cartilage
• General sensory nerves arises from trigeminal nerve
• Special sensory nerves are olfactory nerves which are confined to the upper part of olfactory area

Question 7. Give boundaries, relations & applied anatomy of sphenoidal air sinus
Answer:

• It is a paired sinus

Sphenoidal Air Sinus Boundaries:

• Anteriorly-Roof of the orbit
• Posteriorly- Anterior margin of foramen magnum
• Laterally- pterygoid canal

Sphenoidal Air Sinus Relations:

Sphenoidal Air Sinus Applied Anatomy:

• Infection of a sinus is known as sinusitis
• It causes headache & persistent, thick, purulent discharge from the nose
• It is diagnosed by transillumination & radiography
• A diseased sinus is opaque
• A surgical approach to pituitary gland is via sphenoidal sinus

Question 8. Paranasal air sinus
Answer:

They are air filled spaces present within some bones around the nasal cavities

Paranasal air sinus Types & Their Openings:

Paranasal air sinus Functions:

• Contained air of the sinuses adds humidity & temperature to the inspired air
• Serves as air-conditioning chambers
• Acts as resonating chambers for production of sounds
• Makes the facial bones lighter
• Establish adult contour of the face
• The mucous secretion of the sinuses is drained into the meatuses of the nose

Paranasal air sinus Growth:

• Rudimentary or absent- at birth
• Enlarges- during 6-7 years of age
• Next enlarges- due to

1. 1. Enlargement of bones in adults
   2. Resorption of the surrounding cancellous bone in old age

Question 9. Middle meatus of nose
Answer:

• Lies beneath middle concha
• It presents
  1. Ethamoidal bulla
     • It is rounded elevation produced by middle ethamoidal sinus
  2. Hiatus semilunaris
     • It is deep semicircular sulcus below bulla
  3. Infundibulum
     • It is short passage at anterior end of hiatus

Middle meatus of nose Openings:

Question 10. Ethmoidal air sinuses
Answer:

• Ethmoidal sinuses are numerous small inter communicating spaces within the labyrinth of the ethmoid bone
• Bounded above by orbital plate of frontal bone, behind by sphenoidal conchae and the orbital process of the palatine bone and anterior by the lacrimal bone
• Sinuses are divided into anterior, middle and posterior groups

Question 11. Frontal sinus.
Answer:

• It lies in the frontal bone deep to the superciliary arch
• It is rudimentary at birth & develops at the age of 7-8 years

Frontal sinus Extend:

• Superiorly- Medial end of the eyebrow
• Posteriorly- Medial part of the roof of the orbit

Question 12. Orbital nerve
Answer:

• It is a branch of Pterygopalatine nerve
• A branch of Maxillary nerve given in the Pterygopalatine ganglion
• By means of inferior orbital fissure, it supplies

1. 1. Periosteum of orbit
   2. Posterior ethmoid cells
   3. Orbitalis muscle
   4. Sphenoid sinus

Question 13. Maxillary sinus
Answer:

Maxillary Sinus:

• It is largest of all sinuses
• It lies in the body of maxilla

Maxillary Sinus Opening:

• It opens into middle meatus of nose in the lower part of the hiatus semilunaris
• A second opening is present at the posterior end of hiatus

Question 14. Lymphatic drainage of nasal septum
Answer:

Question 15. Hiatus semilunaris
Answer:

• It is a deep semicircular sulcus below the bulla
• Openings present are
  • Opening of frontal sinus – in anterior part
  • Opening of maxillary sinus – in posterior part
  • Opening of anterior ethmoidal sinus – behind frontal sinus
• Bounded by
  • Inferior and anterior – concave margin of unicate process of ethmoid bone
  • Superior ethmoidal bulla
  • Posterior – inferior nasal concha

Question 16. Give the nerve supply of nasal cavity.
Answer:

1. General sensory nerves Part:

2. Special sensory nerves:

• Olfactory nerve carries sensory sensation.